code: def test_determine_root_gpu_device(devices, expected_root_gpu):
      assert (
          device_parser._determine_root_gpu_device(devices)
          == expected_root_gpu
      )
  
file_path: pytorch-lightning/tests/tests_fabric/utilities/test_device_parser.py
imports: from unittest import mock
  import pytest
  from lightning.fabric.utilities import device_parser
  from lightning.fabric.utilities.exceptions import MisconfigurationException
label_desc: Use image node_id 1 for calling a global function with example usage: test_determine_root_gpu_device(devices, expected_root_gpu) without return types